Liquid crystal display device with first to third subpixels driven in a TN mode and a fourth subpixel drive in ECB mode

ABSTRACT

A liquid crystal display device and a method of manufacturing the liquid crystal device are disclosed. The liquid crystal display device includes a red subpixel, a green subpixel, a blue subpixel, and a viewing angle controlling subpixel. The red, green, and blue subpixels are driven in a TN method, and the viewing angle controlling subpixel is driven in an ECB method. Therefore, the liquid crystal display device provides flexibility in a security range to a user, and not only can be used for one person but also can be used for two or more persons to view an image of high quality without inconvenience while securing security.

CLAIM OF PRIORITY

This application claims benefit of the Korean Patent Application No.129257 filed on Dec. 18, 2006, the entire content of which is herebyincorporated by reference.

BACKGROUND

The present disclosure relates to a liquid crystal display device and amethod for manufacturing the same.

A liquid crystal display (LCD) device, which is one of flat displaydevices recently drawing attention, is a device for applying an electricfield to liquid crystals having both fluidity of liquid and an opticalproperty of crystal to change optical anisotropy. Since the LCD devicehas low power consumption and a small volume, and can be made to havehigh definition in a large size, it is widely used.

Up to now, researches on an LCD device allowing a wider viewing angle isunder active development, but recently, researches have also startedworking on an LCD device having a narrow viewing angle as well as a wideviewing angle is under active development.

For example, in the case where an LCD device is used for protectingcompany secret or the privacy of an individual, information may leak toor the privacy can be violated by a person positioned at an adjacentlocation when the LCD device has only a wide viewing angle.

For this reason, recently, technology for allowing an LCD device to beviewed in a desired viewing angle at a desired time by controlling theLCD device is under active development.

FIG. 1 is a cross-sectional view illustrating a related art LCD devicethat can operate in a wide viewing angle mode and a narrow viewing anglemode.

Referring to FIG. 1, the related art LCD device includes a first liquidcrystal (LC) panel 11 and a second LC panel 12 attached to each other.

The first LC panel 11 includes a first substrate 10 and a secondsubstrate 20 separated by a predetermined distance, facing, and attachedto each other. A first LC layer 30 is interposed between the firstsubstrate 10 and the second substrate 20.

Though not shown, thin film transistors (TFTs) and pixel electrodes canbe formed on the inner surface of the first substrate 10, and colorfilters and a common electrode can be formed on the inner surface of thesecond substrate 20.

The second LC panel 12 is formed on the outer surface of the secondsubstrate 20.

The second LC panel 12 includes a third substrate 50 and a fourthsubstrate 60 separated by a predetermined distance, facing, and attachedto each other. A second LC layer 70 is interposed between the thirdsubstrate 50 and the fourth substrate 60.

Though not shown, a first electrode and a second electrode are formed onthe inner surfaces of the third and fourth substrates 50 and 60,respectively. The first and second electrodes are connected to apredetermined controller to apply an electric field to the second LClayer 70.

The second LC layer 70 is aligned horizontally or vertically by theapplied electric field.

A first polarizer 81 is formed on the outer surface of the firstsubstrate 10 of the first LC panel 11, and a second polarizer 82 isformed on the outer surface of the fourth substrate 60 of the second LCpanel 12.

At least one polarizer can be further provided between the first LCpanel 11 and the second LC panel 12.

During a wide viewing angle mode, the second LC panel 12 directly passesan image generated by the first LC panel 11 regardless of application ofan electric field to the second LC layer 70.

During a narrow viewing angle mode, a predetermined electric field isapplied or not applied to the second LC panel 12 to pass light processedby the second LC panel 12 in only a predetermined direction. Therefore,an image that is generated by the first LC panel 11 and passes throughthe second LC panel 12 can be viewed at a specific narrow viewing angle.

As described above, in the case where a viewing angle controlling LCpanel is attached on a main LC panel providing a primary image tocontrol the viewing angle of a related art LCD device, the viewing anglecontrolling LC panel not only should be additionally manufactured butalso the thickness and weight of a product increase three times or more.

Also, misaligning can be generated while the viewing angle controllingLC panel and the main LC panel are attached to each other. Since lightincident from a backlight unit should always pass through the viewingangle controlling LC panel during a wide viewing angle mode, frontbrightness considerably reduces.

SUMMARY

Embodiments provide a liquid crystal display device that allows a userto selectively view a screen in a wide viewing angle, and a narrowviewing angle, and a method for manufacturing the same.

In one embodiment, a liquid crystal display device includes: a firstsubstrate where first to fourth subpixel regions are defined; a secondsubstrate facing the first substrate, and where the first to fourthsubpixel regions are defined; a first alignment layer aligned to a firstdirection in the first to third subpixel regions, and aligned to a thirddirection different from the first direction in the fourth subpixelregion on the first substrate; a common electrode on the secondsubstrate; a second alignment layer aligned to a second direction in thefirst to third subpixel regions, and aligned to a fourth directiondifferent from the second direction in the fourth subpixel region on thesecond substrate; and a liquid crystal layer between the first andsecond substrates.

In another embodiment, a method for manufacturing a liquid crystaldisplay device includes: preparing first and second substrates wherefirst to fourth subpixel regions are defined; forming a first alignmentlayer on the first substrate; aligning portions of the first alignmentlayer corresponding to the first to third subpixel regions to a firstdirection, and aligning a portion of the first alignment layercorresponding to the fourth subpixel region to a third directiondifferent from the first direction; forming a common electrode on thesecond substrate; forming a second alignment layer on the commonelectrode; aligning portions of the second alignment layer correspondingto the first to third subpixel regions to a second direction, andaligning a portion of the second alignment layer corresponding to thefourth subpixel region to a fourth direction different from the seconddirection; and forming a liquid crystal layer between the first andsecond substrates.

Embodiments provide flexibility in a security range to a user. Accordingto the embodiments, an LCD device can be used not only for one person,and but also for two or more persons without inconvenience. Also,according to the embodiments, an LCD device allows two or more personsto view a high quality image with security.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features will be apparent fromthe description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view illustrating a related art LCD devicedriven in a wide viewing angle mode and a narrow viewing angle mode.

FIG. 2 is a plan view illustrating a first substrate of an LCD deviceaccording to an embodiment.

FIG. 3 is a plan view illustrating a second substrate facing the firstsubstrate of the LCD device of FIG. 2.

FIG. 4 is a cross-sectional view taken along a line I-I′ of FIGS. 2 and3.

FIG. 5 is a cross-sectional view illustrating a portion of a colorfilter substrate (upper substrate) in an LC panel according to anembodiment.

FIG. 6A is a view illustrating a screen of a wide viewing angle mode LCDdevice according to an embodiment, viewed by a lateral viewing angle.

FIG. 6B is a view illustrating a screen of a narrow viewing angle modeLCD device according to an embodiment, viewed by a lateral viewingangle.

FIGS. 7A to 7C are schematic plan views illustrating a process fordifferently aligning a second alignment direction of red, green, andblue subpixels and a fourth alignment direction of a viewing anglecontrolling subpixel in a second substrate of an LCD device according toan embodiment.

FIG. 8 is a table illustrating an example of the transmission axis of apolarizer and the alignment direction of an alignment layer in an LCDdevice according to an embodiment.

FIGS. 9A and 9B are cross-sectional views illustrating an LCD device isdriven in a wide viewing angle mode according to an embodiment.

FIGS. 10A and 10B are cross-sectional views illustrating an LCD deviceis driven in a narrow viewing angle mode according to an embodiment.

FIG. 11 is a plan view of an LCD device according to another embodiment.

FIG. 12 is a plan view of a wiring structure of a second substrate in anLCD device according to an embodiment.

FIG. 13 is a cross-sectional view illustrating a portion of an LCDdevice according to another embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings.

An LCD device according to an embodiment includes a first substrate, asecond substrate, and an LC layer between the first and secondsubstrates. The LCD device also includes a red subpixel Pr, a greensubpixel Pg, a blue subpixel Pb, and a viewing angle controllingsubpixel Pv.

The red subpixel Pr, the green subpixel Pg, and the blue subpixel Pbinclude red, green, and blue color filters, respectively, and theviewing angle controlling subpixel Pv does not include a color filter,or includes a white color filter.

The red subpixel Pr, the green subpixel Pg, and the blue subpixel Pb aredriven in a twisted nematic (TN) method, and the viewing anglecontrolling subpixel Pv is driven in an electrically controllablebirefringence (ECB) method.

The red subpixel Pr, the green subpixel Pg, and the blue subpixel Pb canbe normally white.

An LCD device according to an embodiment can have various arrangementconfigurations in the arrangement order of the red subpixel Pr, thegreen subpixel Pg, the blue subpixel Pb, and the viewing anglecontrolling subpixel Pv. For example, the red, green, and blue subpixelsPr, Pg, Pb, and the viewing angle controlling subpixel Pv can bearranged in a quad type of two rows and two columns, or a stripe type ofone row.

Also, the LCD device can control a viewing angle by making the alignmentdirection of the viewing angle controlling subpixel different from thatof the red, green, and blue subpixels Pr, Pg, and Pb on an alignmentlayer to arrange LC molecules, and driving or not driving the viewingangle controlling subpixel Pv.

The red, green, and blue subpixels Pr, Pg, and Pb are driven in a TNmethod, and the viewing angle controlling subpixel is driven in an ECBmethod.

Embodiments provide flexibility in a security range to a user. Accordingto the embodiments, an LCD device can be used not only for one person,and but also for two or more persons without inconvenience. Also,according to the embodiments, an LCD device allows two or more personsto view a high quality image with security.

The construction of the present disclosure will be described in moredetail and specifically with reference to the accompanying drawings.

The LCD device and the method for manufacturing the same will bedescribed in detail with reference to the accompanying drawings.

FIG. 2 is a plan view illustrating a first substrate of an LCD deviceaccording to an embodiment, FIG. 3 is a plan view illustrating a secondsubstrate facing the first substrate of the LCD device of FIG. 2, andFIG. 4 is a cross-sectional view taken along a line I-I′ of FIGS. 2 and3.

Also, FIG. 5 is a cross-sectional view taken along a line II-II′ of FIG.3.

Referring to FIGS. 2 to 4, the LCD device according to an embodimentincludes red, green, and blue subpixels Pr, Pg, and Pb, and a viewingangle controlling subpixel Pv. The red, green, and blue subpixels Pr,Pg, and Pb are driven in a TN method, and the viewing angle controllingsubpixel is driven in an ECB method.

In the TN method, LC molecules of a nematic state in an LC layer arearranged such that they are continuously twisted along a lighttransmission direction, and when an electric field is applied, thetwisted state of the LC molecules is continuously released and erected,so that the characteristic of transmitted light changes.

When the viewing angle controlling subpixel Pv is in an off-state, theLCD device is driven in a wide viewing angle mode, so that an imagerealized by the red, green, and blue subpixels Pr, Pg, and Pb can beviewed with high quality at a wide viewing angle.

Here, the fact that the viewing angle controlling subpixel Pv is in theoff-state means that the viewing angle controlling subpixel Pv is notdriven.

Also, when the viewing angle controlling subpixel Pv is in an on-state,the LCD device is driven in a narrow viewing angle mode. Since lightthat passes through the viewing angle controlling subpixel Pv serves aslight leakage at a lateral viewing angle through an birefringence effectof LC, an image realized by the red, green, and blue subpixels Pr, Pg,and Pb can be viewed at high quality only at a narrow viewing angle, forexample, a front viewing angle.

The fact that the viewing angle controlling subpixel Pv is in theon-state means that the viewing angle controlling subpixel Pv is driven.

A viewing angle range may be also controlled by controlling a voltageapplied to the viewing angle controlling subpixel Pv.

As illustrated in FIGS. 2 and 4, the first substrate 111 of the LCDdevice includes a plurality of gate lines 112 each being arranged in arow and a plurality of data lines 115 crossing the gate lines 112. Thegate lines 112 and the data lines 115 define the subpixels Pr, Pg, Pb,and Pv.

The gate line 112 includes at least one material of Cu, Al, an aluminumalloy (for example, AlNd), Mo, Cr, Ti, Ta, and MoW.

The data line 115 includes at least one material of Cu, Al, an aluminumalloy (for example, AlNd), Mo, Cr, Ti, Ta, and MoW.

The red, green, and blue subpixels Pr, Pg, and Pb of the subpixels areformed at crossings between the gate lines and the data lines,respectively, and include a TFT for switching a voltage, and a firstpixel electrode 117 connected to the TFT.

The viewing angle controlling subpixel Pv of the subpixels is formed ata crossing between the gate line 112 and the data line 115, and includesa TFT for switching a voltage, and a second pixel electrode 517connected to the TFT and formed inside the viewing angle controllingsubpixel Pv.

Each of the first pixel electrode 117 and the second pixel electrode 517includes at least one of indium-tin-oxide (ITO) and indium-zinc-oxide(IZO).

The TFT includes a gate electrode 112 a extending from the gate line112, a gate insulating layer 113 on the entire surface of the firstsubstrate 111 including the gate electrode 112, a semiconductor layer114 on a portion of the gate insulating layer 113 on the gate electrode112 a, a source electrode 115 a branching off from the data line 115 andformed on one end of the semiconductor layer 114, and a drain electrode115 b separated from the source electrode 115 a and formed on the otherend of the semiconductor layer 114. The semiconductor layer 114 includesamorphous silicon a-Si and impurity-implanted amorphous silicon n+a-Si.

A passivation layer 116 is formed on the first substrate 111 to coverthe TFT. The passivation layer includes a first contact hole 119 a and asecond contact hole 119 b exposing a portion of the drain electrode 115b.

Also, the first pixel electrode 117 is connected to the drain electrode115 b via the first contact hole 119 a, and the second pixel electrode517 is connected to the drain electrode 115 b via the second contacthole 119 b.

The gate insulating layer 113 is interposed between the gate line 112and the data line 115.

The gate insulating layer 113 includes at least one of SiN_(x) andSiO_(x).

The passivation layer 116 includes at least one of SiN_(x) and SiO_(x).

Also, the passivation layer 116 may include at least one ofbenzocyclobutene (BCB) and acryl-based material.

A first alignment layer 171 is formed on the front surface of the firstsubstrate.

Portions of the first alignment layer 171 corresponding to the red,green, and blue subpixels Pr, Pg, and Pb are aligned to a firstalignment direction, and a portion of the first alignment layer 171corresponding to the viewing angle controlling subpixel Pv is aligned toa third alignment direction.

An angle difference between the first alignment direction and the thirdalignment direction may be ±45°.

Referring to FIGS. 3 and 4, a black matrix 122 is formed on a region ofthe second substrate 121 facing the first substrate 111, whichcorresponds to a TFT region, regions of the gate line 112 and the dataline 115, and a light leakage generation region therearound to blockthose regions.

The black matrix 122 can be formed using metal having optical density of3.5 or more such as CrO_(x) and Cr, or a carbon-based organic material,for example.

A red color filter 123 containing pigment realizing red color is formedon the red subpixel Pr on the second substrate 121.

A green color filter 123 containing pigment realizing green color isformed on the green subpixel Pg on the second substrate 121.

A blue color filter 123 containing pigment realizing blue color isformed on the blue subpixel Pb on the second substrate 121.

A white color filter formed of a transparent insulating material can beformed on the viewing angle controlling subpixel Pv on the secondsubstrate 121. A color filter may not be formed on the viewing anglecontrolling subpixel Pv.

An overcoat layer 129 for planarizing a surface may or may not be formedon the entire surface of the second substrate 121.

A first common electrode 124 is formed on portions of the secondsubstrate 121 corresponding to the red, green, and blue subpixels Pr,Pg, and Pb.

Referring to FIG. 5, a second common electrode 524 is insulated orseparated from the first common electrode 124 on a portion of the secondsubstrate 121 corresponding to the viewing angle controlling subpixelPv.

The first common electrode 124 includes at least one of ITO and IZO.

The second common electrode 524 includes at least one of ITO and IZO.

The second common electrode 524 is electrically connected to a commonline 525 to receive a common signal.

The common line 525 can be formed to correspond to the gate line formedon the first substrate 111.

The second common electrode 524 may cover a portion of the common line525 so that the second common electrode 524 is connected to the commonline 525, or the second common electrode 524 is connected to the commonline 525 via a separate contact hole while they are insulated from eachother.

The common line 525 is not connected to the first common electrode 124,but separated by a predetermined distance from the first commonelectrode 124. Preferably, the common line 525 is insulated from thefirst common electrode 124.

Particularly, in the case where the red, green, and blue subpixels Pr,Pg, and Pb, and the viewing angle controlling subpixel Pv are arrangedin a quad type of two rows and two columns, the common line 525 overlapsthe first common electrode 124. Accordingly, an insulating layer needsto be interposed between the common line 525 and the first commonelectrode 124.

The second common electrode 524 and the common line 525 for driving theviewing angle controlling subpixel Pv are formed separately to drive anddelicately control the viewing angle controlling subpixel Pv separatelyfrom the red, green, and blue subpixels Pr, Pg, and Pb. According to anembodiment, the red, green, and blue subpixels Pr, Pg, and Pb, and theviewing angle controlling subpixel Pv are formed in one commonelectrode, and driving of the viewing angle controlling subpixel Pv canbe controlled using the second pixel electrode 517 formed on the firstsubstrate 111.

The common line 525 includes at least one of ITO and IZO havingexcellent light transmittance.

Also, the common line 525 can include at least one of Cu, Al, analuminum alloy (for example, AlNd), Mo, Cr, Ti, Ta, MoW, and an alloythereof.

A second alignment layer 172 is formed the front surface of the secondsubstrate 121.

Portions of the second alignment layer 172 corresponding to the red,green, and blue subpixels Pr, Pg, and Pb are aligned to the secondalignment direction.

A portion of the second alignment layer 172 corresponding to the viewingangle controlling subpixel Pv is aligned to the fourth alignmentdirection.

An angle difference between the second alignment direction and thefourth alignment direction may be ±45°.

The first alignment direction of the first alignment layer 171 may beperpendicular to that of the second alignment layer 172.

Also, the third alignment direction of the first alignment layer 171 maybe opposite to or coincide with the fourth alignment direction of thesecond alignment layer 172.

Therefore, since the portions of the first alignment layer 171corresponding to the red, green, and blue subpixels Pr, Pg, and Pb havean alignment direction perpendicular to the alignment direction of theportions of the second alignment layer 172 corresponding to the red,green, and blue subpixels Pr, Pg, and Pb, LC molecules 132 a of the LClayer 131 interposed between them have a twist angle of 90° and arearranged continuously.

Also, since the portion of the first alignment layer 171 correspondingto the viewing angle controlling subpixel Pv has an alignment directionthat coincides with the alignment direction of the portion of the secondalignment layer 172 corresponding to the viewing angle controllingsubpixel Pv, LC molecules 132 b of the LC layer 131 interposed betweenthem are arranged in the same direction as the coinciding alignmentdirection.

Referring to FIG. 4, a first polarizer 161 is disposed on the outersurface of the first substrate 111, and a second polarizer 162 isdisposed on the outer surface of the second substrate 121.

An angle difference between a first transmission axis of the firstpolarizer 161 and the first alignment direction of the first alignmentlayer 171 is ±45°, and an angle difference between a second transmissionaxis of the second polarizer 162 and the second alignment direction ofthe second alignment layer 172 is ±45°.

Also, the first transmission axis of the first polarizer 161 may beperpendicular to the second transmission axis of the second polarizer162.

The LCD device can be selectively driven in a wide viewing angle modeand a narrow viewing angle mode.

During the wide viewing angle mode, the viewing angle controllingsubpixel of the LCD device is not driven, and a black voltage is appliedto the second pixel electrode 517, or a voltage is not applied, so thata black state is shown.

During the narrow viewing angle mode, the viewing angle controllingsubpixel of the LCD device is driven, a proper voltage is applied to thesecond pixel electrode 517 of the viewing angle controlling subpixel Pv,a vertical electric field is generated to a portion of the LC layercorresponding to the viewing angle controlling subpixel Pv to allow theLC molecules 132 b to erect. Accordingly, a screen viewed by the frontside maintains a black state regardless of voltage application, andphase delay of light is generated at an inclination angle bybirefringence of the LC molecules 132 b, so that light leakage isgenerated at left and right viewing angles.

The LC molecules 132 b of the viewing angle controlling subpixel Pv areinitially aligned to the third and fourth alignment directions, and theinitial alignment direction of the LC molecules 132 b is perpendicularto the first transmission axis of the first polarizer 161 and the secondtransmission axis of the second polarizer 162. Accordingly, when theviewing angle controlling subpixel Pv is not driven, light is blocked bythe second polarizer 162 and a black state is viewed.

Also, when the viewing angle controlling subpixel Pv is driven, apredetermined voltage is applied to the second pixel electrode 517 andthe second common electrode 524, so that a vertical electric field isgenerated between the second pixel electrode 517 and the second commonelectrode 524. Accordingly, the LC molecules 132 b are erected, andlight that has passed through the first transmission axis of thepolarizer is delayed in its phase by the LC molecules to pass throughthe second transmission axis of the second polarizer, and is viewed aslight leakage at a lateral viewing angle.

Though not shown, the LCD device according to an embodiment includes afirst controller for driving the red, green, and blue subpixels Pr, Pg,and Pb to provide a desired image, and a second controller for drivingthe viewing angle controlling subpixel Pv to allow the image to beviewed at only a desired viewing angle.

The second controller can control a range of the viewing angle bycontrolling the intensity of an electric field applied to the viewingangle controlling subpixel Pv.

FIG. 6A is a view illustrating a screen of a wide viewing angle mode LCDdevice according to an embodiment, viewed by a lateral viewing angle,and FIG. 6B is a view illustrating a screen of a narrow viewing anglemode LCD device according to an embodiment, viewed by a lateral viewingangle.

In the case where the LCD device 100 is driven to realize an image, asthe LC molecules 132 a of the LC layer 131 in the red, green, and bluesubpixels Pr, Pg, and Pb continuously arranged with a twist angle of 90°erect, the twisting of the LC molecules is released, and thus a phasedelay value of the LC layer 131 changes, so that a desired image can berealized.

In the case where the viewing angle controlling subpixel Pv iscontrolled in the wide viewing angle mode while the LCD device 100 isdriven to realize the image, a black voltage is or is not applied to theviewing angle controlling subpixel Pv. At this point, since the LCmolecules 132 b of the LC layer 131 in the viewing angle controllingsubpixel Pv maintain arranged in the direction coinciding with the thirdand fourth alignment directions, the LC molecules 132 b directlytransmit light that passes through the first polarizer 161 and isincident onto the LC layer 131, and the light that has passed throughthe LC layer 131 is blocked by the second polarizer 162, so that a blackstate is viewed. The first transmission axis of the first polarizer 161and the second transmission axis of the second polarizer 162 areperpendicular to each other. Therefore, the viewing angle controllingsubpixel Pv does not have an influence on an image realized by the red,green, and blue subpixels Pr, Pg, and Pb, so that the LCD device 100provides a reasonable image that can be viewed at not only a frontviewing angle, but also a laterals viewing angle (wide viewing anglemode. Refer to FIG. 6A).

Here, a fact that a black voltage is or is not applied to the viewingangle controlling subpixel Pv means that the black voltage is or is notapplied to the second pixel electrode 517 so that an electric field isnot applied to a portion of the LC layer corresponding to the viewingangle controlling subpixel Pv.

In the case where the viewing angle controlling subpixel Pv iscontrolled in the narrow viewing angle mode while the LCD device 100 isdriven to realize the image, a white voltage or a voltage lower than thewhite voltage is applied to the viewing angle controlling subpixel Pv.At this point, as the LC molecules 132 b of the LC layer 131 in theviewing angle subpixel Pv arranged along a direction coinciding with thethird and fourth alignment directions erect, light that has passedthrough the first polarizer 161 passes through the LC layer 131 and thesecond polarizer 162 to generate light leakage to the LCD device 100.Particularly, light leakage is generated to left and right lateralviewing angles of the LCD device 100 by controlling a voltage levelapplied to the viewing angle controlling subpixel Pv. That is, since thefront transmission state of the viewing angle controlling subpixel Pvmaintains a black state regardless of voltage application, an image isclearly viewed at the front viewing angle as the red, green, and bluesubpixels Pr, Pg, and Pb are driven. On the other hand, light leakage isgenerated at inclined angles by a phase delay value as a voltage isapplied and a contrast ratio reduces, so that the screen of the LCDdevice 100 is not clearly viewed at lateral viewing angles.

FIGS. 7A to 7C are schematic plan views illustrating a process fordifferently aligning a second alignment direction of red, green, andblue subpixels and a fourth alignment direction of a viewing anglecontrolling subpixel in a second substrate of an LCD device according toan embodiment.

Referring to FIG. 7A, the red, green, and blue subpixels Pr, Pg, and Pb,and the viewing angle controlling subpixel Pv are defined on the secondsubstrate 121.

The red, green, and blue subpixels Pr, Pg, and Pb, and the viewing anglecontrolling subpixel Pv can be arranged in a quad type, or a stripetype.

Also, the viewing angle controlling subpixel Pv can be disposed atrandom, and the red, green, and blue subpixels Pr, Pg, and Pb can bearranged in various configurations.

The second alignment layer 172 is formed on the second substrate 121.

The front surface of the second alignment layer 172 is aligned to thesecond alignment direction.

Therefore, the alignment direction of portions of the second alignmentlayer 172 corresponding to the red, green, and blue subpixels Pr, Pg,and Pb, and the alignment direction of a portion of the second alignmentlayer 172 corresponding to the viewing angle controlling subpixel Pvhave the second alignment direction.

After that, referring to FIG. 7B, a mask 190 having a blocking portionand an opening portion is disposed on the second alignment layer 172aligned to have the second alignment direction.

The blocking portion of the mask 190 corresponds to the red, green, andblue subpixels, and the opening of the mask 190 corresponds to theviewing angle controlling subpixel.

Also, only a portion of the second alignment layer 172 corresponding tothe opening portion of the mask 190, that is, the portion correspondingto the viewing angle controlling subpixel Pv is aligned to a fourthalignment direction.

The mask 190 is removed.

By doing so, referring to FIG. 7C, portions of the second alignmentlayer 172 corresponding to the red, green, and blue subpixels Pr, Pg,and Pb are aligned to have the second alignment direction, and theportion of the second alignment layer 172 corresponding the viewingangle controlling subpixel is aligned to have the fourth alignmentdirection.

The above-described aligning method and other aligning method will bedescribed.

The front surface of the second alignment layer 172 is aligned to thefourth alignment direction.

The mask 190 having the blocking portion only at a portion correspondingto the viewing angle controlling subpixel Pv is disposed on the portionof second alignment layer 172 aligned to the fourth alignment direction.

Portions of the second alignment layer 172 corresponding to the mask 190are aligned to the second alignment direction.

When the mask 190 is removed, the portions of the second alignment layer172 corresponding to the red, green, blue subpixels Pr, Pg, and Pb arealigned to have the second alignment direction, and the portion of thesecond alignment layer 172 corresponding to the viewing anglecontrolling subpixel Pv is aligned to have the fourth alignmentdirection.

An angle difference between the first alignment direction and the fourthalignment direction may be ±45°.

The first alignment layer 171 on the first substrate 111 of the LCDdevice can be aligned according to the above-described method.

Portions of the first alignment layer 171 corresponding to the red,green, and blue subpixels Pr, Pg, and Pb is aligned to the firstalignment direction, and a portion of the first alignment layercorresponding to the viewing angle controlling subpixel Pv is aligned tothe third alignment direction.

An angle difference between the first alignment direction and the thirdalignment direction may be ±45°.

Various methods such as a rubbing method, a light illuminating method,and an ion beam illuminating method can be used for a method foraligning the alignment layer. Also, the various methods can be mixed.

For example, a first alignment process can be performed by aligning analignment layer using the rubbing method, and a second alignment processcan be performed by disposing a mask on a portion of the alignment layerand illuminating light thereto.

For another example, a first alignment process can be performed byaligning an alignment layer using a rubbing method, and a secondalignment process can be performed by disposing a mask on a portion ofthe alignment layer and illuminating an ion beam thereto.

For still another example, a first alignment process can be performed byaligning an alignment layer using a light illuminating method, and asecond alignment process can be performed by disposing a mask on aportion of the alignment layer and illuminating an ion beam thereto.

For still another example, a first alignment process can be performed byaligning an alignment layer using a light illuminating method, and asecond alignment process can be performed by disposing a mask on aportion of the alignment layer and using a rubbing method.

For still another example, a first alignment process can be performed byilluminating an ion beam to an alignment layer to align the alignmentlayer, and a second alignment process can be performed by disposing amask on a portion of the alignment layer and using a rubbing method.

Besides, various methods can be applied to a multi-domain structurewhere an alignment layer is aligned to different alignment directions.

FIG. 8 is a table illustrating an example of the transmission axis of apolarizer and the alignment direction of an alignment layer in an LCDdevice according to an embodiment.

The first polarizer 161 is disposed on the outer surface of the firstsubstrate 111, and the second polarizer 162 is disposed on the outersurface of the second substrate 121 in the LCD device.

The first polarizer 161 has a first polarization axis, and the secondpolarizer 162 has a second polarization axis. The first transmissionaxis may be perpendicular to the second transmission axis.

The first alignment layer 171 is formed on the inner surface of thefirst substrate 111, and the second alignment layer 172 is formed on theinner surface of the second substrate 121.

Portions of the first alignment layer 171 corresponding to the red,green, and blue subpixels Pr, Pg, and Pb are aligned to the firstalignment direction, and portions of the second alignment layer 172corresponding to the red, green, and blue subpixels Pr, Pg, and Pb arealigned to the second alignment direction.

A portion of the first alignment layer 171 corresponding to the viewingangle controlling subpixel Pv is aligned to the third alignmentdirection, and a portion of the second alignment layer 172 correspondingto the viewing angle controlling subpixel Pv is aligned to the fourthalignment direction.

The first alignment direction may be perpendicular to the secondalignment direction.

The third alignment direction may be opposite to or coincide with thefourth alignment direction.

An angle difference between the first alignment direction and the thirdalignment direction may be ±45°.

An angle difference between the second alignment direction and thefourth alignment direction may be ±45°.

Relations between the first transmission axis of the first polarizer161, the first alignment direction and the third alignment direction ofthe first alignment layer 171, the second alignment direction and thefourth alignment direction of the second alignment layer 172, and thesecond transmission axis of the second polarizer 162 are described belowusing an example.

Assuming that the first transmission axis of the first polarizer 161 is0°, the first alignment direction has an alignment axis of −45° withrespect to the first transmission axis.

Also, the second alignment direction of the second alignment layer 172facing the first alignment layer 171 has an alignment axis of +90° withrespect to the first alignment direction.

Since the second transmission axis of the second polarizer 162 has atransmission axis of +90° with respect to the first transmission axis,the second alignment direction of the second alignment layer 172 has analignment axis of −45° with respect to the second transmission axis.

Accordingly, portions of the LC layer 131 corresponding to the red,green, and blue subpixels Pr, Pg, and Pb are arranged in a TN method tohave a twist angle of 90° with respect to a transmission direction oflight.

The third alignment direction of the first alignment layer 171 has analignment axis of −90° with respect to the first transmission axis.

Also, the fourth alignment direction of the second alignment layer 172facing the first alignment layer 171 has an alignment axis of +180° withrespect to the third alignment direction.

Consequently, the alignment directions of the third alignment directionand the fourth alignment direction coincide with each other, and thefourth alignment direction and the second transmission axis of thesecond polarizer coincide with each other.

Accordingly, the directors of LC molecules 132 b in the LC layer of theviewing angle controlling subpixel Pv are arranged to be perpendicularto the first transmission axis of the first polarizer 161, andhorizontal to the transmission axis of the second polarizer 162, the LCmolecules 132 b erect with respect to the surface of the substrate togenerate phase delay when a voltage is applied.

The first and second polarizers 161 and 162 disposed on the outersurfaces of the first and second substrates 111 and 121, respectively,are disposed such that the transmission axes of the first and secondpolarizers 161 and 162 are perpendicular to each other. A portion of thealignment layer corresponding to the viewing angle controlling subpixelPv has an alignment direction parallel to the transmission axis of oneof the first and second polarizers 161 and 162.

Meanwhile, the cell gap of the viewing angle controlling subpixel Pv isequal to or greater than those of the red, green, and blue subpixels Pr,Pg, and Pb.

The LCD device having the above-described construction is driven in awide viewing angle mode and a narrow viewing angle mode. During the wideviewing angle mode, a black voltage is or is not applied to the viewingangle controlling subpixel Pv.

During the narrow viewing angle mode, a proper voltage is applied to thesecond pixel electrode 517 of the viewing angle controlling subpixel Pv.At this point, since a vertical electric field is generated to theviewing angle controlling subpixel Pv to allow LC molecules 132 b toperpendicularly move to the first substrate, a transmission state at thefront maintains a black state regardless of voltage application, andlight leakage is generated to an inclined angle as a voltage is applied.

An LCD device operating in a wide viewing angle mode and an LCD deviceoperating in a narrow viewing angle mode are described below in detail.

FIG. 9A is a cross-sectional view of an LCD device operating in a wideviewing angle mode according to an embodiment.

FIG. 9B is a cross-sectional view of an LCD device operating in a wideviewing angle mode according to an embodiment.

The LCD device according to an embodiment includes the first substrate111, the second substrate 121, and the LC layer 131 interposed betweenthe first and second substrates 111 and 121. A red subpixel Pr, a greensubpixel Pg, a blue subpixel Pb, and a viewing angle controllingsubpixel Pv are defined.

The red, green, and blue subpixels Pr, Pg, and Pb are driven in a TNmode, and the viewing angle controlling subpixel Pv is driven in an ECBmode.

When the viewing angle controlling subpixel Pv is in an off-state, theLCD device is driven in the wide viewing angle mode by the red, green,and blue subpixels Pr, Pg, and Pb.

In the LCD device, a black voltage is applied to the viewing anglecontrolling subpixel Pv so that the viewing angle controlling subpixelPv becomes a black state. When a voltage is not applied to the red,green, and blue subpixels Pr, Pg, and Pb, a white state is displayed onthe whole by a twist arrangement of the LC molecules 132 a.

Referring to FIG. 9A, when a voltage is not applied to the red, green,and blue subpixels Pr, Pg, and Pb during the wide viewing angle mode,light directly passes through due to a twist arrangement of the LCmolecules 132 a, so that a normally white state is viewed.

Here, since the LCD device is driven in the wide viewing angle mode, avoltage is or is not applied to the viewing angle controlling subpixelPv and a black state is displayed.

Referring to FIG. 9B, a voltage is applied to the red, green, and bluesubpixels Pr, Pg, and Pb during a wide viewing angle mode, so that agray scale is displayed on a screen.

Since the LCD device is driven in the wide viewing angle mode, a blackvoltage is or is not applied to the viewing angle controlling subpixelPv to display a black state. Accordingly, gray scale displayed on thescreen by the red, green, and blue subpixels Pr, Pg, and Pb is directlydisplayed not only on a front viewing angle but also on a lateralviewing angle.

As the LC molecules 132 b of the LC layer 131 in the red, green, andblue subpixels Pr, Pg, and Pb continuously arranged with a twist angleof 90° erect, the twisting is released, and accordingly, the lighttransmittance of the LC molecules 132 a changes, so that a desired imagecan be realized.

During the wide viewing angle mode, a black voltage is or is not appliedto the viewing angle controlling subpixel Pv.

At this point, since the LC molecules 132 b of the LC layer 131 in theviewing angle controlling subpixel Pv maintain the state where the LCmolecules 132 b are arranged to a direction coinciding with the thirdand fourth alignment directions, the LC molecules 132 b transmits lightthat passes through the first polarizer 161 and is incident to the LClayer 131, and the light that has passed through the LC layer 131 isblocked by the second polarizer 162, so that light is not transmittedthrough the second polarizer 162 and thus a black state is displayed.

The first transmission axis of the first polarizer 161 is perpendicularto the second transmission axis of the second polarizer 162. Therefore,since the viewing angle controlling subpixel Pv does not have aninfluence on an image realized by the red, green, and blue subpixels Pr,Pg, and Pb, an image is properly viewed not only at a front viewingangle, but also at a lateral viewing angle in the LCD device.

That is, during the wide viewing angle mode, the red, green, and bluesubpixels Pr, Pg, and Pb become a white state when a voltage is notapplied thereto, and the red, green, and blue subpixels Pr, Pg, and Pbdisplay a gray scale uniformly over an entire viewing angle when avoltage is applied in the LCD device.

Meanwhile, while the viewing angle controlling subpixel Pv is in anon-state, the LCD device generates light leakage at the lateral viewingangle, and thus is driven in the narrow viewing angle mode.

While the viewing angle controlling subpixel Pv is driven in the narrowviewing angle mode, a viewing angle range is controlled according to atleast one voltage level applied to the second pixel electrode 517.

FIG. 10A is a cross-sectional view of the LCD device of FIG. 4 operatingin a narrow viewing angle mode according to an embodiment.

FIG. 10B is a cross-sectional view of the LCD device of FIG. 4 operatingin a narrow viewing angle mode according to an embodiment.

The LCD device according to an embodiment includes the first substrate111, the second substrate 121, and the LC layer 131 interposed betweenthe first and second substrates 111 and 121. A red subpixel Pr, a greensubpixel Pg, a blue subpixel Pb, and a viewing angle controllingsubpixel Pv are defined.

The red, green, and blue subpixels Pr, Pg, and Pb are driven in a TNmode, and the viewing angle controlling subpixel Pv is driven in an ECBmode.

During the narrow viewing angle mode, since the viewing anglecontrolling subpixel Pv of the LCD device transmits light through thelateral sides of the screen, an image displayed by the red, green, andblue subpixels Pr, Pg, and Pb is clearly viewed at a front viewing anglebut the image is not clearly viewed at the lateral viewing anglesbecause a contrast ratio reduces due to light leakage generated by theviewing angle controlling subpixel Pv.

Referring to FIG. 10A, since an electric field is not applied toportions of the LC layer 131 corresponding to the red, green, and bluesubpixels Pr, Pg, and Pb during an off 0-state, the LC molecules 132 amaintain an initial arrangement state where the LC molecules 132 a inthe LC layer 131 are continuously arranged with a twist angle of 90°, anormally white mode is displayed.

Also, since the viewing angle controlling subpixel Pv is in an on-state,the viewing angle controlling subpixel Pv transmits light through thelateral viewing angles of the LCD device.

That is, while the viewing angle controlling subpixel Pv is in theoff-state, the LC molecules are arranged in the same direction as thealignment directions of the first and alignment layers 171 and 172. Onthe other hand, while the viewing angle controlling subpixel Pv is inthe on-state, an electric field is applied to the LC layer 131 and thusthe LC molecules 132 b erect to transmit light through the lateralsides.

Therefore, light leakage is generated at left and right viewing anglesby the erecting LC molecules 132 in the viewing angle controllingsubpixel Pv, so that a contrast ratio reduces, which reduces imagequality at left and right viewing angles.

Also, referring to FIG. 10B, during the on-state, twisting of an LCmolecule arrangement in portions of the LC layer 131 corresponding tothe red, green, and blue subpixels Pr, Pg, and Pb is released and thuserects to display a gray scale.

Also, when the viewing angle controlling subpixel Pv is in the on-state,an electric field is applied to the LC layer 131, so that the LCmolecules 132 b that have been aligned to the same direction as thealignment directions of the first and second alignment layers 171 and172 erect to transmit light through the lateral sides.

Therefore, an image generated by the red, green, and blue subpixels Pr,Pg, and Pb is directly displayed at the front viewing angle, butretardation is greatly generated at the later sides by the erecting LCmolecules 132 in the viewing angle controlling subpixel Pv at the leftand right viewing angles, so that a contrast ratio reduces and thusimage quality reduces at the left and right viewing angles.

When a voltage applied to the viewing angle controlling subpixel Pv isproperly controlled during the narrow viewing angle mode, an electricfield applied to a portion of the LC layer corresponding to the viewingangle controlling subpixel can be controlled, and a retardation value ofthe LC molecules 132 at the left and right viewing angle directions canbe controlled.

Therefore, a viewing angle allowing a user to view a screen can becontrolled to a desired degree by the user, and flexibility in asecurity range is provided to the user of the LCD device. Also, the LCDdevice not only can be used for one person but also can be used for twoor more persons to view an image of high quality without inconveniencewhile securing security.

FIG. 11 is a plan view of an LCD device according to another embodiment.

Referring to FIG. 11, the LCD device according to an embodiment caninclude red, green, and blue subpixels Pr, Pg, and Pb, and a viewingangle controlling subpixel Pv arranged in a row.

Referring to FIG. 11, the viewing angle controlling subpixel can bedisposed at random, and the positions of the red, green, and bluesubpixels Pr, Pg, and Pb can be also arranged in various configurations.

FIG. 12 is a plan view of a wiring structure of a second substrate in anLCD device according to an embodiment.

Referring to FIG. 12, the second substrate 121 is divided into a screendisplay region A where LCs are driven to display a screen, and an outerregion B, which is a non-display region.

Red, green, and blue color filters R, G, and B are formed in the screendisplay region A of the second substrate 121 to correspond to red,green, and blue subpixels Pr, Pg, and Pb, respectively.

A white color filter for generating white light is or is not formed inthe viewing angle controlling subpixel Pv.

A first common electrode 124 is formed on portions of the secondsubstrate 121 corresponding to the red, green, and blue subpixels Pr,Pg, and Pb.

A second common electrode 524 is formed on a portion of the secondsubstrate 121 corresponding to the viewing angle controlling subpixelPv.

The first common electrode 124 and the second common electrode 524include at least one of ITO, IZO, and ITZO.

The first common electrode 124 and the second common electrode 524 areseparated from each other.

The first common electrode 124 and the second common electrode 524 canbe insulated from each other by an insulating layer.

The first common electrode 124 is formed on an entire surface of thesecond substrate 121, and a portion of the first common electrode 124corresponding to the viewing angle controlling subpixel Pv can be open.

The second common electrode 524 is electrically connected to a commonline, which applies a common signal for viewing control to the secondcommon electrode 524.

The common line is connected to the common signal for viewing control,and formed long over the outer region of the second substrate.

The common line can overlap the first common electrode, and aninsulating material may be interposed between the common line and thefirst common electrode.

A conductive line can be formed along the outer region of the secondsubstrate, and connected to the common line formed on the secondsubstrate.

In the case where the common line 525 is formed of the same material asthat of the second common electrode 524, the conductive line 531 can becollectively patterned using the same material as that of the commonelectrode 524 for viewing control.

Also, the conductive line 531 can be formed of a separate metal line,and the common line 525 can be connected to the conductive line 531.

The first common electrode 124 receives a common signal from a firstcontroller of the first substrate 111. For this purpose, at least onefirst conducive connecting pattern 533 a (for example, Ag dot) forconnecting the first common electrode 124 with the first controller canbe formed at a predetermined position.

For example, the first conductive connecting pattern 533 a is formedbetween the first common electrode 124 and the first substrate 111 atthe outer side of a seal pattern for attaching the first substrate 111to the second substrate 121.

The second common electrode 524 receives a common signal for viewingcontrol from a second controller of the first substrate 111. For thispurpose, at least one second conductive connecting pattern 533 b forconnecting the second common electrode 524 with the second controllercan be formed at a predetermined position.

The first conductive connecting pattern 533 a and the second conductiveconnecting pattern 533 b may be formed such that they do not contacteach other or do not generate signal interference.

The LCD device according to an embodiment can be driven in the wideviewing angle mode or the narrow viewing angle mode. To selectivelyswitch the LCD device to the wide viewing angle mode and the narrowviewing angle mode, a viewing angle mode switching operation isperformed using a selection signal. When the wide viewing angle mode isselected by the selection signal, an electric field is not applied to aportion of the LC layer corresponding to the viewing angle controllingsubpixel Pv. On the other hand, when the narrow viewing angle mode isselected, an electric field is applied to the portion of the LC layercorresponding to the viewing angle controlling subpixel Pv, so thatlight that has passed through the portion of the LC layer generateslight leakage at the lateral viewing angles.

When the narrow viewing angle mode is selected, a proper driving voltageis applied to the viewing angle controlling subpixel Pv. The drivingvoltage is input from the second controller of the first substrate 111,and connected to the conductive line 531 through the second conductiveconnecting pattern 533 b conducting the first and second substrates 111and 121, and applied to the second common electrode 524 through thecommon line 525 electrically connected with the conductive line 531.

The intensity of an electric field applied to the portion of the LClayer 131 corresponding to the viewing angle controlling subpixel Pv canbe controlled by controlling a common voltage applied to the secondcommon electrode 524 and a pixel voltage applied to the second pixelelectrode 517. Therefore, since retardation values of LC molecules 132 bin a portion of the LC layer 131 corresponding to the viewing anglecontrolling subpixel Pv at left and right viewing angle directions canbe controlled, an LCD device having various viewing angle ranges can berealized.

Meanwhile, various patterns that can prevent electrostatic discharge canbe further connected to the conductive line 531.

FIG. 13 is a cross-sectional view illustrating a portion of an LCDdevice according to another embodiment.

Detailed descriptions of the same parts as those of the previousembodiment are omitted, and only the characteristics of the presentembodiment are described.

Referring to FIG. 13, the LCD device includes red, green, and bluesubpixels Pr, Pg, and Pb, and a viewing angle controlling subpixel Pv.The red, green, and blue subpixels Pr, Pg, and Pb are driven in a TNmethod, and the viewing angle controlling subpixel Pv is driven in anECB method.

One common electrode 124 can be formed on portions of a second substrate121 corresponding to the red, green, and blue subpixels Pr, Pg, and Pband the viewing angle controlling subpixel Pv.

A viewing angle range can be controlled by controlling a voltage appliedto a second pixel electrode 517 of the viewing angle controllingsubpixel Pv.

According to an embodiment, a wide viewing angle mode and a narrowviewing angle mode can be selectively realized in the LCD device, sothat personal security can be secured.

According to an embodiment, a viewing angle can be controlled by makingthe alignment direction of the viewing angle controlling subpixeldifferent from those of the red, green, and blue subpixels in analignment layer of the LCD device, driving the viewing angle controllingsubpixel in an ECB mode, and driving the red, green, and blue subpixelsin a TN mode. Accordingly, the LCD device can be easily manufactured.

Also, according to an embodiment, a viewing angle is controlled byadding a viewing angle controlling subpixel inside an LC panel, so thata process is simplified.

Also, according to an embodiment, a separate viewing angle control layerdoes not need to be added, so that an LCD device having excellent lightefficiency and having a lightweight and slim profile can be provided.

Also, the LCD device according to an embodiment provides flexibility ina security range to a user, and not only can be used for one person butalso can be used for two or more persons to view an image of highquality without inconvenience while securing security.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

1. A liquid crystal display device comprising: a first substrate wherefirst to fourth subpixel regions are defined; a pixel electrode disposedon each of the first to fourth subpixel regions; a second substratefacing the first substrate, and where the first to fourth subpixelregions are defined; a first alignment layer aligned to a firstdirection in the first to third subpixel regions, and aligned to a thirddirection different from the first direction in the fourth subpixelregion on the first substrate; a common electrode on the secondsubstrate; a second alignment layer aligned to a second direction in thefirst to third subpixel regions, and aligned to a fourth directiondifferent from the second direction in the fourth subpixel region on thesecond substrate; and a liquid crystal layer between the first andsecond substrates, wherein the first to third subpixels are driven in aTN (Twisted Nematic) method and the fourth subpixel is driven in ECB(Electrically Controllable Birefringence) method, wherein the fourthsubpixel is a viewing angle controlling subpixel to select a wideviewing angle mode or a narrow viewing angle mode, wherein the commonelectrode comprises: a first common electrode formed on an entiresurface of the second substrate and having an open portion correspondingto the fourth subpixel; a second common electrode on the open portion ofthe first common electrode corresponding to the fourth subpixel regionand separated from the first common electrode; and a common lineconnected to the second common electrode and formed on a black matrix ofthe second substrate corresponded to a gate line, wherein a range of theviewing angle is controlled by controlling a common voltage and a pixelvoltage applied to the fourth subpixel.
 2. The device according to claim1, further comprising: a first polarizer on an outer surface of thefirst substrate, the first polarizer having a first transmission axis;and a second polarizer on an outer surface of the second substrate, thesecond polarizer having a second transmission axis, wherein the firsttransmission axis and the second transmission axis are perpendicular toeach other.
 3. The device according to claim 1, further comprising: afirst polarizer on an outer surface of the first substrate, the firstpolarizer having a first transmission axis; and a second polarizer on anouter surface of the second substrate, the second polarizer having asecond transmission axis, wherein one of the first transmission axis andthe second transmission axis coincides with the third direction or isperpendicular to the third direction.
 4. The device according to claim1, wherein the first direction and the second direction areperpendicular to each other.
 5. The device according to claim 1, whereinthe third direction and the fourth direction are the same or opposite toeach other.
 6. The device according to claim 1, wherein directors ofliquid crystal molecules of portions of the liquid crystal layercorresponding to the first to third subpixel regions are continuouslytwisted from the first direction to the second direction, the directorsbeing arranged from the first substrate to the second substrate.
 7. Thedevice according to claim 1, wherein directors of liquid crystalmolecules of a portion of the liquid crystal layer corresponding to thefourth subpixel region are horizontally arranged from the thirddirection to the fourth direction, the directors being arranged from thefirst substrate to the second substrate.
 8. The device according toclaim 1, wherein a cell gap of the fourth subpixel region is thickerthan cell gaps of the first to third subpixel regions by a thickness ofthe color filters.
 9. The device according to claim 1, furthercomprising: a first controller for driving the first to third subpixelregions; a second controller for driving the fourth subpixel region tocontrol a viewing angle range.
 10. The device according to claim 1,further comprising: a conductive line on an outer block of the secondsubstrate, the conductive line being electrically connected to thecommon line; a first conductive connecting pattern conducting to theconductive line; and a second conductive connecting pattern conductingto the first common electrode, the second conductive connecting patternbeing separated from the first conductive connecting pattern.